OKDEK LXIV. COMPOSITE COMPOSITE-FAMILY. 



165 



cylindrical, with the linear, green scales in a single row. Pappus abundant, 

 white, very soft 



GROUP 4. 

 Central flowers perfect ; marginal mostly enlarged and sterile. 



40. CE.NTABBEA. Receptacle bristly. Pappus composed of capillary, rough 

 bristles, in several rows. 



41. AMBERBOA. Pappus consisting of oblong, or obovate, chaffy scales; 

 rarely small or none. 



GKOUP 5. 



Heads consisting wholly of either staminate or pistillate flowers (rarely in 

 Antenuaria a few staminate flowers in the centre of the pistillate heads). 



34. ANTEXNARIA. Plants with dioecious flowers. Keceptacle somewhat 

 convex, alveolate. Woolly herbs. 



36. XANTHIUM. Plants with monoecious flowers. Staminate in short, ter- 

 minal racemes; pistillate ones in small clusters, at the base of the staminate. 

 Fertile heads 2-flowered. covered with hooked prickles, forming a burr. Pappus 

 none. 



87. AMBROSIA. Flowers monoecious. Sterile flowers nodding, in long ra- 

 cemes. Fertile flowers in a closed, 1-flowered involucre, axillary, near the 

 base of the sterile raceme. 



6. Lower leaves at least opposite or verticiUate. 



GROUP. 6. 

 Central and marginal flowers perfect 



2. EUPATORIUM. Heads 3 many-flowered. Involucre-scales 8 or more. 

 Pappus simple, capillary. Eeceptacle naked. Erect herbs. 



3. MIKANIA. Heads 4-flowered. Involucre-scales 4. Keceptacle naked. 

 Pappus sim.p!e, capillary. Climbing herbs. 



29. BIDENS. Heads many-flowered. Keceptacle chaffy. Pappus consisting 

 of 2 4, stilt; barbed awns. 



GROUP 7. 



Central flowers staminate ; marginal ones pistillate, fertile. 

 38. IVA. Heads small, on short recurved peduncles, racemose, forming 

 leafy panicles. Shrubby at base. 



.3. Central flowers tubular ; marginal or ray flowers ligulaie. 

 a. Leaves all alternate or radical. 



GKOUP 8. 

 Kays yellow, pistillate. Disk-flowers perfect, 



13. SOLIDAGO. Heads small. Kays about 5, short. Involucre-scales imbri- 

 .nte. Keceptacle flatfish, alveolate. 



14. INULA. Heads very large. Kays very numerous. Involucre-scales 

 imbricate. Keceptacle flat 



21. HKLENIUM. Kays numerous, 8 5-cleft at summit Involucre of re- 

 llexed scales. Keceptacle subglobose. naked. 



30. SENECIO. Heads in flat corymbs. Involucre-scales in a single row. 

 Kays entire. Keceptacle flat 



GROUP 9. 

 Rays not yellow, pistillate. Disk-flowers perfect 



* Receptacle alveolate. 



6. ASTER. Heads corymbose or paniculate. Pappus simple, capillary. 

 Aehenia compressed, smooth. 



7. SERicocARPi-8. Heads corymbose. Pappus simple, capillary. Achenia 

 obconic, densely silky. 



8. Dii'LOPAppi-8. Heads rather large, corymbose, or solitary. Involucre 

 scales appressed. Pappus double ; outer series very short; inner of capillary 

 bristles. 



10. CAI.LISTEPIIUS. Heads very large, solitary on the branchlets. Involucre 

 scales with large, leafy, spreading tips. Pappus double ; outer series of short, 

 chaffy scales; inner series of long capillary, deciduous bristles. 



18. SOLIDAGO. Heads small, in axillary racemes. Kays few, short Pap- 

 pus simple, capillary. 



* * Keceptacle naked. 



9. ERIGERON. Ray flowers very numerous and narrow. Pappus simple or 

 double. Keceptacle flat. 



11. BELLIS. Leaves all radical. Heads solitary. Receptacle conical. Pap- 

 pus none. 



25. LEUCANTHEMUM. Involucre broad, depressed at the centre. Pappus 

 none. 



26. PYRKTHRUM. Involucre hemispherical. Pappus reduced to a mem- 

 branous border or crown. 



27. CHRYSANTHEMUM. Involucre hemispherical. Pappus none. 



* * * Receptacle chaf f y. 



22. ANTHEMIS. Rays numerous. Receptacle convex. Pappus reduced to 

 a slight border, crowning the achenia. 



24. AcniLLiA. Kays 510. Receptacle flat. Pappua none. 



GROUP 10. 

 Rays neutral. Disk flowers perfect 



23. MARTJTA. Receptacle conical, more or less chaffy. Rays white. 



17. RUDBECKIA. Involucre-scales in 2 series. Receptacle conical, chaffy 

 Pappus none, or a mere border. Rays yellow. 



GROUP 11. 



Rays pistillate. Disk-flowers staminate. 

 6. TUSSILAQO. Acaulescent Rays very narrow, in many rows. 



39. CALENDULA. Involucre-scales nearly equal, in 2 rows. Pappus none. 

 6. Lower leaves, at least, opposite. 



GEOUP 12. 



Rays pistillate. Disk-flowers perfect 



12. DAHLIA. Involucre-scales in 2 rows. Receptacle chaffy. Pappus 

 none. "Leaves pinnate. 



16. IlELi6i>sis. Involucre-scales imbricated in several rows. Receptacle 

 chaffy, conical. Pappus none. 



18. ZINNIA. Involucre-scales imbricated in several rows. Receptacle 

 chaffy, conical. Pappus of the disk consisting of 2 erect awns. Leaves entire. 



20. TAGETES. Involucre-scales in 1 row. Keceptacle naked. Pappus of 5 

 erect awns. Leaves pinnately-parted. 



GROUP 13. 

 Rays neutral. Disk- flowers perfect 



19. HELIANTIIUS. Involucre-scales in several rows. Receptacle with per- 

 sistent chaff. Pappus persistent, of 2 deciduous, chaffy awns. 



28. COREOPSIS. Involucre-scales in 2 series. Receptacle with deciduous 

 chaff. Achenia compressed. Pappus reduced to 2 teeth, or none. 



29. BiDENS. Involucre-scales in 2 series. Receptacle chaffy. Pappus con- 

 sisting of 2 4 barbed awns. Achenia quadrangular. 



SUBOKDEB II. Ligulifl6ra3. 

 Flowers all ligulate. 



GROUP 1. 

 Plants acaulescent. 



4S. KRIGIA. Involucre-scales equal, in 2 rows. Achenia turbinate. Pap- 

 pus double ; outer series of broad scales ; inner of slender bristles. 



49. LEONTODON. Involucre-scales imbricate; outer ones very short Pap- 

 pus plumose ; bristles in a single series. Achenia scarcely beaked. 



55. TARAXACUM. Involucre-scales in 2 series; inner series appressed; outer 

 reflexed. Achenia with a long beak, bearing a capillary, copious pappus. 



GROUP 2. 

 Plants caulescent Heads yellow. 



63. HIERAOIUM. Achenia oblong, not beaked. Pappus-bristles tawny, ca- 

 pillary, in a single series. Leaves toothed or entire. 



51. LACTUCA. Achenia compressed, with a long filiform beak. Pappus 

 verv abundant, white and soft. 



56. SONCHUS. Achenia compressed, not beaked. Pappus very abundant, 

 white, soft, capillary. 



GROUP 8. 



Plants caulescent. Heads not yellow. 



47. CICHOUIUM. Involucre-scales in 2 series. Pappus of very short scales. 

 Achenia not beaked. Leaves runcinate. 



50. TRAGOPOGON. Involucre-scales in a single series. Achenia with a long, 

 filiform beak. Pappus plumose. Leaves linear. 



52. MULGEDIUM. Involucre-scales in 2 series ; outer ones short Achenia 

 flattisb, with short thick beaks. Pappus soft, capillary. 



64. NABALUS. Involucre-scales cylindric, in a single row, with a few ap- 

 pressed bractlets at base. Achenia not beaked. Heads mostly in axillary 

 racemes. 



1. VERN6NIA. 



Heads 15 many-flowered. Involucre of many ovate, ap- 

 pressed, imbricated scales, shorter than the flowers. Receptacle 

 naked. Achenia cylindrical, ribbed. Pappus double ; the outer 

 short, chaffy; the inner capillary. Per. 



1. V. Noveboracensis. 



Iron-weed. 



Stem erect, branching above ; leaves alternate, lanceolate, serrulate, pubes- 

 cent underneath ; heads rather large, dark purple, in terminal, compound, flat- 

 topped cymes ; scales of the involucre terminating in a long awn, or bristle- 

 like appendage. A tall plant, 4 6 feet high, in swamps, with numerous dark 

 purple heads. Quite showy. Aug. Sep. 



2. EUPAT6RIUM. 



Heads 3 many-flowered. Involucre cylindrical, imbricate, 

 Receptacle flat. Style much exsert. Pappus simple, roughish. 

 Achenia 5-angled. Per. 



1. E. purpureum. 



Trumpet-weed. 



Stem tall, simple ; leaves varying from broad-ovate to lanceolate, acuminate, 

 veiny, somewhat rough, serrate or toothed, 86 in a whorl ; heads 5 10-flow- 

 ered ; scales of the involucre purplish, numerous, closely imbricated in several 

 rows of unequal length ; flowers light purple, in dense compound corymbs. An 

 exceedingly variable plant. The stem ranges from 2 10 feet high, is solid or 

 hollow, spotted or without spots, and sometimes dotted ; leaves also variable in 

 shape and size. Low ground. Very common. Aug. Sep. 



2. E. teucrifolium. 



Pubescent and somewhat rough ; leaves opposite, ovate or ovate-lanceolate, 

 obtuse at base, sessile, veiny ; upper ones alternate and nearly entire ; heads in 

 corymbs, with a few unequal branches, about 8-flowered, white : ecaies about 



